* {
    list-style: none;
}

.all {
    display: flex;
    justify-content: space-around;
    align-items: center;
    width: 1500px;
    height: 800px;
    margin: 0 auto;
    box-sizing: border-box;
    border: 1px solid black;
}

.devices {
    width: 400px;
    height: 780px;
    border-radius: 20px;
    box-sizing: border-box;
    border: 1px solid black;
}

.devices .text {
    width: 90%;
    height: 40px;
    margin: 10px auto;
}

.devices .item {
    display: flex;
    justify-content: space-around;
    align-items: center;
    text-align: center;
    width: 90%;
    height: 60px;
    box-sizing: border-box;
    border-radius: 10px;
    margin: 5px auto;
    border: 1px solid black;
}

.devices .item .device {
    width: 40%;
    height: 90%;
    line-height: 54px;
}

.devices .item .user {
    width: 40%;
    height: 90%;
    line-height: 54px;
}

.students {
    width: 1050px;
    height: 780px;
    box-sizing: border-box;
    border: 1px solid black;
    border-radius: 10px;
}

.students .text {
    width: 90%;
    height: 40px;
    text-align: center;
    line-height: 40px;
    border-radius: 10px;
    margin: 10px auto;
}

.students .item {
    float: left;
    text-align: center;
    line-height: 80px;
    width: 100px;
    height: 80px;
    box-sizing: border-box;
    border: 1px solid rgb(0, 0, 0);
    border-radius: 20px;
    margin: 15px;
}